Flame-retardant environment-friendly plastic material and preparation method thereof
By preparing flame-retardant and environmentally friendly plastic materials containing modified bamboo fiber and flame retardant synergists, the problems of poor flame retardancy, insufficient antibacterial properties, and poor aging resistance of polyester biodegradable plastics have been solved, and high-performance environmentally friendly plastic materials have been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUNAN SHENGXINRUTAI BIOTECHNOLOGY CO LTD
- Filing Date
- 2026-04-07
- Publication Date
- 2026-05-12
AI Technical Summary
Existing polyester biodegradable plastic materials have problems such as poor flame retardancy, easy melting and dripping, insufficient antibacterial properties and poor aging resistance, which limit their application in situations with high fire risk and high antibacterial requirements.
Flame-retardant and environmentally friendly plastic materials are prepared by extrusion granulation using components such as polylactic acid, starch, PBAT, flame retardant, flame retardant synergist and modified bamboo fiber. The modified bamboo fiber surface is grafted with quaternary ammonium groups and fluorinated segments to improve antibacterial properties, and the flame retardant synergist enhances flame retardancy and aging resistance.
It achieves excellent mechanical strength, antibacterial effect, heat resistance and UV aging resistance of the material, improves the flame retardancy and antibacterial properties of polyester materials, reduces the risk of dripping, and enhances the overall performance stability of the material.
Smart Images
Figure CN122011712A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, and in particular to a flame-retardant and environmentally friendly plastic material and its preparation method. Background Technology
[0002] In recent years, the problem of "white pollution" caused by non-degradable waste plastics has become increasingly serious, attracting widespread attention globally. To address this environmental challenge, countries around the world have successively introduced relevant regulations to restrict or ban the use of non-degradable plastic packaging products. Meanwhile, the manufacture of traditional plastics relies on non-renewable petroleum resources, whose reserves are dwindling. Therefore, the development of environmentally friendly, degradable plastics made from renewable resources is urgently needed.
[0003] Polyester biodegradable plastics (such as polylactic acid (PLA), polybutylene adipate / terephthalate (PBAT), and polybutylene succinate (PBS)) are typical bio-based or biodegradable materials, widely used in food packaging, textiles, and daily-use plastics due to their excellent biodegradability, light transmittance, and processing properties. PLA, as a representative bio-based polyester, possesses high tensile strength and good transparency; PBAT, with its excellent flexibility and film-forming properties, is widely used in the packaging field. However, these polyester materials generally suffer from the following common problems: their molecular backbone consists of linear aliphatic chains or aliphatic-aromatic chains containing only C, H, and O elements, resulting in poor intrinsic flame retardancy and a tendency to produce dripping during combustion, posing a fire hazard. Simultaneously, the surface of polyester materials is susceptible to contamination by harmful bacteria, which multiply rapidly under suitable humidity conditions, affecting hygiene and limiting their application in situations requiring high antibacterial properties. Therefore, developing an environmentally friendly polyester biodegradable plastic material that combines mechanical properties, flame retardancy, antibacterial properties, and aging resistance is essential. Summary of the Invention
[0004] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a flame-retardant and environmentally friendly plastic material that combines mechanical properties, flame-retardant properties, antibacterial properties and aging resistance.
[0005] The second objective of this invention is to provide a simple method for preparing flame-retardant and environmentally friendly plastic materials.
[0006] One of the objectives of this invention is achieved through the following technical solution: A flame-retardant and environmentally friendly plastic material, by weight, comprises the following components: 50-70 parts polylactic acid, 20-30 parts starch, 10-15 parts PBAT, 8-12 parts flame retardant, 1-3 parts flame retardant synergist, 3-8 parts modified bamboo fiber, 2-7 parts plasticizer, and 1-5 parts lubricant.
[0007] Furthermore, the preparation process of the flame retardant synergist is as follows: Gallic acid and (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid were added to toluene / dioxane solution, and then anhydrous sodium sulfate was added for reflux reaction. After purification, the flame retardant synergist was obtained. The structural formula of the flame retardant synergist is: .
[0008] Furthermore, the molar ratio of gallic acid, (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid, and anhydrous sodium sulfate is 0.3:(0.62-0.65):(19-22).
[0009] Furthermore, the preparation process of the modified bamboo fiber is as follows: (1) Add the pretreated bamboo fiber to water, add diethylaminomethyltriethoxysilane to react, filter after the reaction is completed, wash, and vacuum dry to obtain amination bamboo fiber; (2) The aminated bamboo fiber was added to acetonitrile, and 4-bromophenyl perfluoro(1,4-dimethyl-2,5-dioxaoctyl) one was added to react. After the reaction was completed, the mixture was filtered, washed, and vacuum dried to obtain the modified bamboo fiber.
[0010] Furthermore, in step (1), the mass ratio of the pretreated bamboo fiber to diethylaminomethyltriethoxysilane is 1:(0.12-0.34); the reaction temperature is 60-65℃ and the reaction time is 5-8h.
[0011] This invention first activates bamboo fiber by alkali treatment, then reacts it with diethylaminomethyltriethoxysilane to obtain amination bamboo fiber, and then quaternizes it with 4-bromophenylperfluoro(1,4-dimethyl-2,5-dioxaoctyl) to obtain modified bamboo fiber with surface grafted quaternary ammonium groups and fluorine-containing segments.
[0012] Furthermore, the method for preparing the pretreated bamboo fiber is as follows: Bamboo fiber powder is added to sodium hydroxide solution, stirred at 50-55℃ for 1-2 hours, filtered, washed, and vacuum dried to obtain the pretreated bamboo fiber.
[0013] Furthermore, the mass ratio of the bamboo fiber powder to the sodium hydroxide solution is 1:(9-12); the concentration of the sodium hydroxide solution is 0.1 mol / L.
[0014] Furthermore, in step (2), the mass ratio of the amination of bamboo fiber to 4-bromophenyl perfluoro(1,4-dimethyl-2,5-dioxaoctyl) ketone is 1:(0.4-1.2); the reaction temperature is 70-75℃ and the reaction time is 24-28h.
[0015] Furthermore, the polylactic acid has a weight-average molecular weight of (1-1.5) × 10⁻⁶. 5 The starch is selected from corn starch, wheat starch, and potato starch; the plasticizer is tributyl citrate or polyethylene glycol; the lubricant is selected from zinc stearate, lauric acid, and paraffin wax; and the flame retardant is ammonium polyphosphate or melamine phosphate.
[0016] The second objective of this invention is achieved by the following technical solution: The preparation method of the above-mentioned flame-retardant and environmentally friendly plastic material includes the following steps: Mix the components evenly according to the stated weight proportions, then extrude and granulate.
[0017] Furthermore, the temperatures of each zone during the extrusion granulation process are as follows: Zone 1: 140-160℃, Zone 2: 165-180℃, Zone 3: 185-200℃, Zone 4: 205-212℃, Zone 5: 215-220℃, and the die head: 215-225℃.
[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a flame-retardant and environmentally friendly plastic material, comprising the following raw materials: polylactic acid, starch, PBAT, flame retardant, flame retardant synergist, modified bamboo fiber, etc. This environmentally friendly plastic material possesses excellent mechanical strength, antibacterial effect, heat resistance, UV aging resistance, and flame retardant properties.
[0019] 2. This invention improves the mechanical strength, antibacterial effect, and heat resistance of plastic materials by adding modified bamboo fiber. Specifically, the quaternary ammonium groups on the surface of the modified bamboo fiber possess highly efficient antibacterial activity. They can adsorb and disrupt microbial cell membranes through electrostatic interactions, synergistically enhancing the overall antibacterial performance of the material with the flavonoids and polyphenols naturally present in the bamboo fiber. Furthermore, the fluorinated segments grafted onto the surface of the modified bamboo fiber have extremely low surface energy, which not only enhances the compatibility between the bamboo fiber and the matrix but also significantly improves the hydrophobicity of the material, effectively inhibiting moisture penetration and reducing bacterial growth caused by moisture absorption. In addition, the fluorinated structure in the modified bamboo fiber has high chemical bond energy and excellent thermal stability, making it difficult to decompose at high temperatures, which helps improve the heat resistance of the material; while the bamboo fiber itself has high strength and modulus, and can form a three-dimensional support network in the matrix, which helps improve the mechanical strength and structural stability of the material.
[0020] 3. This invention improves the mechanical strength, UV aging resistance, and flame retardant properties of plastic materials by adding a flame retardant synergist. Specifically, this invention synthesizes a boron-containing flame retardant synergist with gallic acid as the backbone, which complements the flame retardant and effectively solves the problems of low flame retardant efficiency and easy dripping in polylactic acid materials. Its mechanism of action is as follows: First, in the early stage of combustion, the hindered phenolic structure in the flame retardant synergist molecule acts as a hydrogen donor, efficiently capturing active free radicals such as ·OH, ·H, and ·O generated during combustion, interrupting the chain reaction and inhibiting flame propagation; Second, in the middle and late stages of combustion, the benzene ring and benzopyran heterocycle in the flame retardant synergist molecule form a dense aromatic char layer through cross-linking reaction, isolating heat, oxygen, and combustible gases, and delaying the pyrolysis of the matrix; while boron is converted into B2O3 glassy substance, filling the cracks in the char layer and improving its strength, and can also wrap the molten part, effectively inhibiting dripping and secondary combustion. Meanwhile, this flame retardant synergist exhibits good compatibility with the matrix, avoiding the decline in flame retardant efficiency and mechanical properties caused by phase separation. Furthermore, the hindered phenolic structure contained in this flame retardant synergist can delay photo-oxidative aging by scavenging free radicals, while the conjugated benzene heterocyclic structure in the gallic acid-derived framework has strong UV absorption capacity. The two synergistically enhance the material's resistance to UV aging. Attached Figure Description
[0021] Figure 1 SEM image of the modified bamboo fiber prepared in Example 4 of this invention. Detailed Implementation
[0022] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.
[0023] The weight-average molecular weight of the polylactic acid of this invention is 1×10⁻⁶. 5 The weight-average molecular weight of PBAT is 1×10⁻⁶. 5 The diameter of bamboo fiber is 1μm.
[0024] The starch is corn starch; the plasticizer is polyethylene glycol; the lubricant is zinc stearate; and the flame retardant is ammonium polyphosphate.
[0025] (a) Preparation example Preparation Example 1 This preparation example provides a flame retardant synergist, and the preparation process is as follows: A mixture of gallic acid, (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid, anhydrous sodium sulfate, and toluene in a ratio of 0.3 mmol:0.64 mmol:20 mmol:45 mL was prepared. Gallic acid (CAS: 548-05-0) and (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid were dissolved in a toluene / dioxane solution (v / v, 4:1). Anhydrous sodium sulfate was then added, and the mixture was reacted overnight under reflux. The mixture was filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography to obtain a flame retardant synergist (yield 88.1%). The NMR and mass spectrometry results are shown below. 1 HNMR: (C 49 H 46 O 14 B2, 400MHz, DMSO-d6) δ: 1.40 (s, 36H), 6.99 (s, 4H), 7.11 (s, 1H), 7.30 (s, 2H), 7.45 (s, 1H), 8.73 (s, 1H), 10.44 (s, 1H). MS (ESI) m / z=880.31 [M].
[0026] Preparation Example 2 This preparation example provides a flame retardant synergist, and the preparation process is as follows: The ratio of gallic acid, (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid, anhydrous sodium sulfate, and toluene was 0.3 mmol:0.62 mmol:19 mmol:30 mL. Gallic acid and (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid were dissolved in toluene / dioxane solution (v / v, 4:1), and then anhydrous sodium sulfate was added. The mixture was reacted overnight under reflux. After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by column chromatography to obtain the flame retardant synergist (yield 86.5%). The NMR and mass spectrometry results were the same as in Preparation Example 1.
[0027] Preparation Example 3 This preparation example provides a flame retardant synergist, and the preparation process is as follows: The ratio of gallic acid, (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid, anhydrous sodium sulfate, and toluene was 0.3 mmol: 0.65 mmol: 22 mmol: 50 mL. Gallic acid and (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid were dissolved in toluene / dioxane solution (v / v, 4:1), and then anhydrous sodium sulfate was added. The mixture was reacted overnight under reflux. After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by column chromatography to obtain the flame retardant synergist (yield 84.8%). The NMR and mass spectrometry results were the same as in Preparation Example 1.
[0028] Preparation Example 4 This preparation example provides a modified bamboo fiber, and the preparation process is as follows: (1) Bamboo fiber powder was ultrasonically dispersed in 0.1 mol / L sodium hydroxide solution at a mass ratio of 1:10, stirred at 54°C for 1.5 h, filtered, washed with deionized water until neutral, and vacuum dried to obtain pretreated bamboo fiber; the pretreated bamboo fiber was ultrasonically dispersed in water at a mass ratio of 1:0.3:12, diethylaminomethyltriethoxysilane was added, reacted at 63°C for 7 h, filtered after the reaction was completed, washed with water, and vacuum dried to obtain amination bamboo fiber; (2) The aminated bamboo fiber, 4-bromophenylperfluoro(1,4-dimethyl-2,5-dioxaoctyl) ketone, and acetonitrile were ultrasonically dispersed in acetonitrile at a ratio of 1 g: 12 g: 40 mL. 4-bromophenylperfluoro(1,4-dimethyl-2,5-dioxaoctyl) ketone (CAS: 67727-74-6) was added, and the reaction was carried out at 73 °C for 26 h. After the reaction was completed, the mixture was filtered, washed with acetonitrile, and vacuum dried to obtain the modified bamboo fiber. The SEM image of the modified bamboo fiber is shown below. Figure 1 .
[0029] Preparation Example 5 This preparation example provides a modified bamboo fiber, and the preparation process is as follows: (1) Bamboo fiber powder and sodium hydroxide solution were ultrasonically dispersed in 0.1 mol / L sodium hydroxide solution at a mass ratio of 1:9. The mixture was stirred at 50°C for 2 hours, filtered, washed with deionized water until neutral, and vacuum dried to obtain pretreated bamboo fiber. The pretreated bamboo fiber was ultrasonically dispersed in water at a mass ratio of 1:0.12:10. Diethylaminomethyltriethoxysilane was added and reacted at 60°C for 8 hours. After the reaction was completed, the mixture was filtered, washed with water, and vacuum dried to obtain amination bamboo fiber. (2) The modified bamboo fiber was ultrasonically dispersed in acetonitrile with a ratio of 1 g: 0.4 g: 30 mL of amination bamboo fiber, 4-bromophenylperfluoro(1,4-dimethyl-2,5-dioxaoctyl) ketone, and acetonitrile. The mixture was then added and reacted at 70 °C for 24 h. After the reaction was completed, the mixture was filtered, washed with acetonitrile, and dried under vacuum to obtain the modified bamboo fiber.
[0030] Preparation Example 6 This preparation example provides a modified bamboo fiber, and the preparation process is as follows: (1) Bamboo fiber powder was ultrasonically dispersed in 0.1 mol / L sodium hydroxide solution at a mass ratio of 1:12, stirred at 55°C for 1 h, filtered, washed with deionized water until neutral, and vacuum dried to obtain pretreated bamboo fiber; the pretreated bamboo fiber was ultrasonically dispersed in water at a mass ratio of 1:0.34:15, diethylaminomethyltriethoxysilane was added, reacted at 65°C for 5 h, filtered after the reaction was completed, washed with water, and vacuum dried to obtain amination bamboo fiber; (2) The modified bamboo fiber was ultrasonically dispersed in acetonitrile with a ratio of 1 g: 1.2 g: 50 mL of amination bamboo fiber, 4-bromophenylperfluoro(1,4-dimethyl-2,5-dioxaoctyl) ketone, and acetonitrile. The mixture was then added and reacted at 75 °C for 24 h. After the reaction was completed, the mixture was filtered, washed with acetonitrile, and dried under vacuum to obtain the modified bamboo fiber.
[0031] (II) Implementation Examples Example 1 This embodiment provides a flame-retardant and environmentally friendly plastic material, which, by weight, includes the following components: 62 parts polylactic acid, 27 parts starch, 13 parts PBAT, 10 parts flame retardant, 2 parts flame retardant synergist of Preparation Example 1, 5 parts modified bamboo fiber of Preparation Example 4, 6 parts plasticizer, and 4 parts lubricant.
[0032] This embodiment also provides a method for preparing the above-mentioned flame-retardant and environmentally friendly plastic material, including the following steps: Mix the components evenly according to the stated weight proportions, then add them to a twin-screw extruder for extrusion granulation. The twin-screw extruder operates at a speed of 50 r / min. The temperatures of each zone during the extrusion granulation process are as follows: Zone 1: 140-160℃, Zone 2: 165-180℃, Zone 3: 185-200℃, Zone 4: 205-212℃, Zone 5: 215-220℃, and the die head: 215-225℃.
[0033] Example 2 This embodiment provides a flame-retardant and environmentally friendly plastic material, which, by weight, includes the following components: 50 parts polylactic acid, 20 parts starch, 10 parts PBAT, 8 parts flame retardant, 1 part flame retardant synergist of Preparation Example 2, 3 parts modified bamboo fiber of Preparation Example 5, 2 parts plasticizer, and 1 part lubricant.
[0034] This embodiment also provides a method for preparing the above-mentioned flame-retardant and environmentally friendly plastic material, including the following steps: Mix the components evenly according to the stated weight proportions, then add them to a twin-screw extruder for extrusion granulation. The twin-screw extruder operates at a speed of 50 r / min. The temperatures of each zone during the extrusion granulation process are as follows: Zone 1: 140-160℃, Zone 2: 165-180℃, Zone 3: 185-200℃, Zone 4: 205-212℃, Zone 5: 215-220℃, and the die head: 215-225℃.
[0035] Example 3 This embodiment provides a flame-retardant and environmentally friendly plastic material, which, by weight, includes the following components: 50-70 parts polylactic acid, 30 parts starch, 15 parts PBAT, 12 parts flame retardant, 3 parts flame retardant synergist of Preparation Example 3, 8 parts modified bamboo fiber of Preparation Example 6, 7 parts plasticizer, and 5 parts lubricant.
[0036] This embodiment also provides a method for preparing the above-mentioned flame-retardant and environmentally friendly plastic material, including the following steps: Mix the components evenly according to the stated weight proportions, then add them to a twin-screw extruder for extrusion granulation. The twin-screw extruder operates at a speed of 50 r / min. The temperatures of each zone during the extrusion granulation process are as follows: Zone 1: 140-160℃, Zone 2: 165-180℃, Zone 3: 185-200℃, Zone 4: 205-212℃, Zone 5: 215-220℃, and the die head: 215-225℃.
[0037] (III) Comparative Example Comparative Example 1 Based on Example 1, the modified bamboo fiber in Preparation Example 4 was replaced with bamboo fiber to form Comparative Example 1.
[0038] Comparative Example 2 Based on Example 1, the flame retardant synergist of Preparation Example 1 was omitted to form Comparative Example 2.
[0039] Comparative Example 3 Based on Example 1, the flame retardant synergist in Preparation Example 1 was replaced with (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid to form Comparative Example 3.
[0040] (iv) Examples of Results The test methods for tensile strength and elongation at break are GB / T 1040.3-2006, with a tensile rate of 2 mm / min. The test method for antibacterial activity is QB / T 2591-2003, and the test strains are Staphylococcus aureus and Escherichia coli. Heat resistance: Heat resistance is characterized by tensile strength retention rate. The test temperature is 55±2℃, the relative humidity is 75%, and the test time is 400h. Tensile strength retention rate (%) = tensile strength of the sample after the test / tensile strength of the sample before the test. UV resistance: The tensile strength retention rate is used to characterize UV resistance. The test temperature is 80℃ and the tritium lamp aging treatment is 1200h. Tensile strength retention rate (%) = tensile strength of the sample after the test / tensile strength of the sample before the test. The test method for limiting oxygen index is GB / T 2406.1-2008, and the test results are shown in Table 1.
[0041] Table 1 As shown in Table 1, compared to Comparative Example 1, the material obtained in Example 1 exhibits superior mechanical strength, antibacterial effect, and heat resistance. Further analysis reveals that the quaternary ammonium groups on the surface of the modified bamboo fiber possess highly efficient antibacterial activity. They can adsorb and disrupt microbial cell membranes through electrostatic interactions, synergistically enhancing the overall antibacterial performance of the material with the flavonoids and polyphenols naturally present in the bamboo fiber. Furthermore, the fluorinated segments grafted onto the surface of the modified bamboo fiber have extremely low surface energy, which not only enhances the compatibility between the bamboo fiber and the matrix but also significantly improves the hydrophobicity of the material, effectively inhibiting moisture penetration and reducing bacterial growth caused by moisture absorption. In addition, the high chemical bond energy and excellent thermal stability of the fluorinated structure in the modified bamboo fiber make it less prone to decomposition at high temperatures, contributing to improved heat resistance. The bamboo fiber itself has high strength and modulus, forming a three-dimensional support network in the matrix, which helps improve the mechanical strength and structural stability of the material.
[0042] Compared with Comparative Examples 2-3, the material obtained in Example 1 exhibits superior mechanical strength, UV aging resistance, and flame retardant properties. Further analysis reveals that this invention synthesizes a boron-containing flame retardant synergist using gallic acid as the backbone, complementing the flame retardant and effectively addressing the shortcomings of low flame retardant efficiency and easy dripping in polylactic acid materials. Its mechanism of action is as follows: Firstly, in the early stage of combustion, the hindered phenolic structure in the flame retardant synergist molecule acts as a hydrogen donor, efficiently capturing active free radicals such as ·OH, ·H, and ·O generated during combustion, interrupting the chain reaction and inhibiting flame propagation. Secondly, in the middle and later stages of combustion, the benzene ring and benzopyran heterocycle in the flame retardant synergist molecule form a dense aromatic char layer through cross-linking reactions, isolating heat, oxygen, and combustible gases, and delaying matrix pyrolysis. Meanwhile, boron is converted into B2O3 glassy material, filling the cracks in the char layer and enhancing its strength, and can also encapsulate the molten portion, effectively inhibiting dripping and secondary combustion. Meanwhile, this flame retardant synergist exhibits good compatibility with the matrix, avoiding the decline in flame retardant efficiency and mechanical properties caused by phase separation. Furthermore, the hindered phenolic structure contained in this flame retardant synergist can delay photo-oxidative aging by scavenging free radicals, while the conjugated benzene heterocyclic structure in the gallic acid-derived framework has strong UV absorption capacity. The two synergistically enhance the material's resistance to UV aging.
[0043] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.
Claims
1. A flame-retardant and environmentally friendly plastic material, characterized in that, By weight, it includes the following components: 50-70 parts polylactic acid, 20-30 parts starch, 10-15 parts PBAT, 8-12 parts flame retardant, 1-3 parts flame retardant synergist, 3-8 parts modified bamboo fiber, 2-7 parts plasticizer, and 1-5 parts lubricant.
2. The flame-retardant and environmentally friendly plastic material according to claim 1, characterized in that, The preparation process of the flame retardant synergist is as follows: Gallic acid and (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid were added to toluene / dioxane solution, and then anhydrous sodium sulfate was added for reflux reaction. After purification, the flame retardant synergist was obtained. The structural formula of the flame retardant synergist is: 。 3. The flame-retardant and environmentally friendly plastic material according to claim 2, characterized in that, The molar ratio of gallic acid, (3,5-di-tert-butyl-4-hydroxyphenyl)boronic acid, and anhydrous sodium sulfate is 0.3:(0.62-0.65):(19-22).
4. The flame-retardant and environmentally friendly plastic material according to claim 1, characterized in that, The preparation process of the modified bamboo fiber is as follows: (1) Add the pretreated bamboo fiber to water, add diethylaminomethyltriethoxysilane to react, filter after the reaction is complete, wash, and vacuum dry to obtain amination bamboo fiber; (2) The aminated bamboo fiber was added to acetonitrile, and 4-bromophenyl perfluoro(1,4-dimethyl-2,5-dioxaoctyl) one was added to react. After the reaction was completed, the mixture was filtered, washed, and vacuum dried to obtain the modified bamboo fiber.
5. The flame-retardant and environmentally friendly plastic material according to claim 4, characterized in that, In step (1), the mass ratio of the pretreated bamboo fiber to diethylaminomethyltriethoxysilane is 1:(0.12-0.34); the reaction temperature is 60-65℃ and the reaction time is 5-8h.
6. The flame-retardant and environmentally friendly plastic material according to claim 5, characterized in that, The method for preparing the pretreated bamboo fiber is as follows: Bamboo fiber powder is added to sodium hydroxide solution, stirred at 50-55℃ for 1-2 hours, filtered, washed, and vacuum dried to obtain the pretreated bamboo fiber.
7. The flame-retardant and environmentally friendly plastic material according to claim 4, characterized in that, In step (2), the mass ratio of the amination of bamboo fiber to 4-bromophenyl perfluoro(1,4-dimethyl-2,5-dioxaoctyl) ketone is 1:(0.4-1.2); the reaction temperature is 70-75℃ and the reaction time is 24-28h.
8. The flame-retardant and environmentally friendly plastic material according to claim 4, characterized in that, The polylactic acid has a weight-average molecular weight of (1-1.5)×10⁻⁶. 5 The starch is selected from corn starch, wheat starch, and potato starch; the plasticizer is tributyl citrate or polyethylene glycol; the lubricant is selected from zinc stearate, lauric acid, and paraffin wax; and the flame retardant is ammonium polyphosphate or melamine phosphate.
9. The method for preparing the flame-retardant and environmentally friendly plastic material according to any one of claims 1-8, characterized in that, Includes the following steps: Mix the components evenly according to the stated weight proportions, then extrude and granulate.
10. The method for preparing the flame-retardant and environmentally friendly plastic material according to claim 9, characterized in that, The temperatures in each zone during the extrusion granulation process are as follows: Zone 1: 140-160℃, Zone 2: 165-180℃, Zone 3: 185-200℃, Zone 4: 205-212℃, Zone 5: 215-220℃, and the die head: 215-225℃.